The long-term goal of this proposal is to elucidate the mechanisms that regulate cellular energy balance. Here, we are focusing on energy regulation in adipose tissue with a weighted focus on brown fat. Interest in brown fat bioenergetics is rapidly gaining momentum because of the recent realization that adult humans possess a significant quantity of brown fat or brown fat-like cells that may exhibit metabolically favorable fat burning properties. It is speculated that therapeutically increasing brown fat energy expenditure could defend against obesity. Importantly however, very little is known about the molecular signals that control energy expenditure in adipose tissue, or brown fat differentiation and function. The objective of this proposal is to test the hypothesis that the mechanistic target of rapamycin complex 2 (mTORC2) is a critical regulator of metabolism and energy expenditure in brown fat. To test this, we are taking a multidisciplinary approach utilizing genetically engineered mice, primary cell lines, and pharmacological agents to study the mechanisms by which mTORC2 and its substrates regulate energy balance in adipose tissue. Our work is yielding very interesting and unexpected preliminary findings that suggest inhibiting mTORC2 reprograms cellular metabolism and may increase brown fat activity. In Specific Aim 1, we elucidate the mechanism by which mTORC2 reprograms metabolism. In Specific Aim 2, we test the in vivo relevance of our hypothesis and our preliminary findings using novel mouse models. In Specific Aim 3, we ask if pharmacologically inhibiting mTORC2 can treat pathological fat accumulation. Elucidating the metabolic regulatory circuits under mTORC2 control in brown fat will have important implications in advancing therapies targeting cellular bioenergetics.